Skip to content

Brain Signals to Computer: The Role of Electrodes in the BCI System

February 11, 2025
Brain Signals to Computer: The Role of Electrodes in the BCI System

What is BCI?

Brain-Computer Interface (BCI) is a technology field that aims to transfer brain signals directly to computer systems. This system allows individuals to interact with pixel-based digital environments by recording and analyzing brain waves. The basic principles of BCI revolve around the perception of neurological signals and the interpretation of these signals. Individuals’ thoughts and intentions are transferred to digital platforms through electrons, inferences, and feedback.

BCI systems generally use electrodes to detect brain waves. These electrodes operate through a series of sensors placed on the brain surface. Brain symbols and electrical potentials can be collected by electroencephalography (EEG) or invasive methods. This collected data is transmitted to a computer system and converted into digital commands representing the individual’s intentions or movements. Thus, individuals can control computer systems using their thoughts.

BCI technology plays an important role in the healthcare sector, especially in the treatment of neurological diseases. Individuals with conditions such as paralysis and ALS (Amyotrophic Lateral Sclerosis) regain the use of their immobile limbs or their ability to communicate thanks to BCI systems. In addition, the use of BCI in areas such as the gaming industry and virtual reality enriches people’s interaction with the digital world, and it is predicted that it will become more widespread in the future. These systems have the potential to transform human-machine interaction, doing so in both entertainment and healthcare.

Brain Electrical Activities: Basic Information

The brain is one of the most complex organs in the body, and it performs its functions through electrical activities. Nerve cells, called neurons, generate electrical signals to provide information transmission. These signals establish a continuous communication network between neurons in different regions of the brain. These signals, acting as generators and commanders, form the basis of mental processes, movements, and feelings.

Electrical activities in the brain are usually expressed with wave forms, and these waves are divided into various categories according to their frequencies. For example, alpha waves (8-12 Hz) are prominent during rest and relaxation periods, while beta waves (13-30 Hz) occur during active thinking and problem-solving moments. Delta waves (0.5-4 Hz) appear during deep sleep, and theta waves (4-8 Hz) appear during deep meditation or light sleep. Each electrical wave reflects the brain’s general state, wakefulness, or mental activity level at that moment.

The electrical activities of the brain affect not only mental processes but also physical responses. For example, high-frequency beta waves that occur during stress can increase heart rate, while alpha waves seen during relaxation create a general feeling of calmness. Monitoring these types of electrical activities is of critical importance for the diagnosis and treatment of many diseases. Methods such as electroencephalography (EEG) record these signals, helping to analyze and evaluate brain condition. As a result, brain electrical activities play a decisive role in human behavior and mood. Therefore, the interpretation of these signals is vital in both scientific research and clinical applications.

Working Principle of Electrodes

Electrodes play a critical role in the Brain-Computer Interface (BCI) system. These electrodes are designed to detect brain activities and transmit this data to the computer. According to the basic working principle, the electrodes measure the neuronal activities in the brain and generate electrical signals. These signals allow the electrical activities occurring in certain regions of the brain to be recorded.

The detection method is generally divided into two main types: invasive and non-invasive. Invasive electrodes provide the highest sensitivity by being placed inside the brain tissue. These types of electrodes are usually placed with surgical operations and collect signals directly from neurons. Non-invasive electrodes are placed on the scalp and measure brain waves with methods such as electroencephalography (EEG). The placement of both types of electrodes should be carefully planned to obtain accurate data.

The electrode placement techniques vary according to the intended use. In the placement of non-invasive electrodes, special gels or adhesives can be used to ensure full contact with the scalp. Invasive electrodes are directed to specific brain regions and fixed with surgical methods. This method allows high-quality and accurate signals to be obtained. After the electrodes collect brain signals, the signals are transmitted to the computer for analysis and interpretation. This stage is of great importance in understanding brain activities and making the BCI system work effectively.

Conversion of Brain Signals into Digital Data

The conversion of brain signals into digital data constitutes the most critical stage of brain-computer interface (BCI) systems. This transformation involves the transition of electrical signals produced by the brain from analog form to digital form. The first step is the collection of brain signals through electrodes. Electrodes detect neural activities by being placed on or deep into the brain surface. These obtained analog signals are collected over a certain period of time and then processed through special software.

The basic process used in converting analog signals to digital data is digitization. This process enables analog signals to be represented in digital format by measuring them with certain points. During digitization, there are two main stages: sampling and quantization. While sampling means cutting the signal by taking it at certain intervals, quantization is the process of converting these samples into numerical values. This process transforms the signal into a more processable and analyzable format, making it usable in computer systems.

The algorithms used during this transformation are of great importance to ensure that brain signals are analyzed efficiently. These algorithms, which include machine learning and artificial intelligence techniques, are designed to interpret brain activities and classify these signals for use in various applications. As a result, brain signals are converted into digital data, providing individuals with more control and understanding over their brain activities.

Application Areas: Healthcare and Technology

The BCI system, which transmits brain signals to the computer, has an important place in the field of healthcare. Especially the use of this system in the rehabilitation process of paralyzed individuals increases the quality of life of patients and accelerates physical rehabilitation processes. BCI systems can determine the thoughts or intentions of the user by analyzing the signals coming from the brain with the help of electrodes such as electromyography (EMG) and electroencephalography (EEG). In this way, paralyzed patients can provide control in virtual environments or robotic prostheses through these systems, taking a big step towards regaining their physical movements.

In addition, the potential uses of the BCI system in neurological diseases are also remarkable. By monitoring the progression of diseases such as Alzheimer’s and Parkinson’s, it allows treatment processes to be managed more effectively. While electrodes track patients’ brain activity, they also provide the opportunity to assess whether they are responding to treatment. These applications help create personalized care plans by enabling the collection of personal health data.

In industrial areas, BCI systems and electrodes are also used to improve human-machine interaction. Especially in dangerous tasks that need to be performed in factories, it has great potential for workers to control machines with their brain signals. These innovations provide users with a safer working environment while also offering the opportunity to increase productivity.

As a result, the applications of the BCI system in the fields of health and technology contain various benefits and seem to have the potential to unlock more innovation in the future, raising living standards.

Challenges and Limitations

Although Brain-Computer Interface (BCI) systems, which transmit brain signals to the computer, offer many advantages, they face various challenges and limitations. These difficulties include issues that need to be addressed both technically and ethically. In particular, the placement of electrodes is a critical factor that directly affects the efficiency and accuracy of the system. During the placement of electrodes, some difficulties may be experienced depending on the sensitivity of the brain tissue; for example, wrongly placed electrodes may cause unwanted signals to be obtained.

In addition, signal noise is a significant problem for BCI systems. Brain signals are at risk of mixing with environmental noise and other biological signals. This situation can reduce the quality of the received signals and create significant difficulties in the signal processing stage. The management of signal noise is of vital importance in increasing the effectiveness of such systems.

Ethical and security concerns are also important limitations faced by BCI systems. There are concerns about privacy and the protection of individuals’ personal data during the collection and analysis of brain signals. The use of these systems, in particular, may allow the reading of human mood and thoughts, which may potentially increase the risk of misuse. Therefore, a careful ethical review is required in the process of developing and implementing such technologies.

Future Perspective: Innovations in BCI Technology

In the future, BCI (Brain-Computer Interface) technology promises significant innovations and developments. Artificial intelligence integration is at the center of research in this area. This integration can greatly improve the user experience by enabling BCI systems to read and interpret brain signals more efficiently. Thanks to artificial intelligence and machine learning algorithms, these systems can offer personalized feedback. This will allow the development of solutions specific to individuals’ needs.

In addition, new techniques, including image processing, have the potential to increase the accuracy of BCI systems. Advanced sensors and signal processing methods can analyze brain activities more accurately and thus provide more accurate results. With the development of smart electrodes, it is expected that less invasive methods will emerge. This will both offer a more comfortable experience for users and make long-term use of electrodes possible.

In addition, the scope of human-computer interaction will expand, and more areas in daily life will be integrated with BCI technology. For example, BCI systems developed for visually impaired individuals can increase individuals’ independence by increasing environmental perception. The use of BCI systems in education and rehabilitation processes can offer innovative methods that accelerate learning and healing.

The future of BCI technology will be shaped by scientists’ and engineers’ continuous focus on innovative research. Investments in this area will play an important role in meeting community health and special needs.

User Experiences: Real-Life Examples

The BCI (Brain-Computer Interface) system, which transmits brain signals to the computer, is reshaping users’ interactions with technology. Individuals who experience the benefits provided by this system mostly provide positive feedback, but the difficulties they face in the development process are also of vital importance. The difficulties that users face when taking their first steps towards the BCI system are usually related to the adaptation process. This process requires perception, motor skills, and mental concentration. It may take time for users to develop these skills, which can initially create stress and frustration.

One user stated that trying to command the computer with brain signals required intense attention and mental effort. However, he stated that this process became easier over time and that adapting to the system offered many benefits. For example, this user shared his experience of playing games with the BCI system; he emphasized that although he had difficulty at first, he was able to transfer signals more effectively after a few weeks and thus began to exhibit a more successful performance.

In addition to negative experiences, users are also excited about the opportunities offered by the system. Another individual using the BCI system shared that while he had difficulty using traditional computers due to his physical disabilities, he found the opportunity to access technology more independently thanks to the BCI. This situation shows the positive effects of the BCI system, offering users a new standard of living.

The Importance and Future of BCI

The BCI (Brain-Computer Interface) system, which transmits brain signals to the computer, is one of the leading innovations in neurotechnology. The importance of this system lies in its capacity to analyze the complex activities of the human brain and directly integrate individuals’ thoughts and feelings into digital platforms. Thanks to BCI, people with limited mobility, such as paralyzed individuals, can communicate with computers and improve their daily lives through brain waves. Thus, the social and individual benefits of the BCI system are noteworthy.

The future of BCI looks quite promising with the influence of constantly developing technologies. In addition to the applications of artificial intelligence and machine learning, the more effective use of neural networks in BCI systems in the coming periods can offer new opportunities to evaluate individuals’ thoughts more accurately and quickly. In addition, these systems will become more user-friendly over time, which will make it easier to adopt by the general public.

In terms of social impacts, BCI systems have the potential to revolutionize the fields of education, rehabilitation, and communication. In the field of education, it will be possible to make students’ learning processes more effective by personalizing teaching methods. In rehabilitation processes, motivating patients through brain signals and developing new learning pathways can accelerate treatment processes. As a result, the importance and future of the BCI system will increasingly stand out with the contributions it makes to human life.